Discovery Bay, CA— fire, flood & earthquake hazard information
Discovery Bay is a unincorporated community in Contra Costa County in the San Francisco Bay Area, covering about 5.6 square miles. This page summarizes what official government maps show for Discovery Bay: CAL FIRE fire hazard severity zones, FEMA flood zones, state seismic hazard zones, dam inundation areas, airport noise contours, and air-quality indicators. Figures are the share of Discovery Bay’s area that falls inside each mapped zone.
View Discovery Bay on the interactive map → to check any specific address, free.
Wildfire hazard severity zones
CAL FIRE's current Fire Hazard Severity Zone maps do not designate any zones within Discovery Bay. Individual properties near the boundary can still fall inside a neighboring zone — check the exact address on the map.
FEMA flood zones
31% of Discovery Bay lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 17% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
| Special Flood Hazard Area (100-yr) | 31% |
| 0.2% annual chance (500-yr) | 17% |
Earthquake faults & seismic zones
The nearest mapped fault, the Midland fault zone, is about 2.0 mi (3.3 km) from the center of Discovery Bay. 82% of its area is in a state-designated liquefaction zone of required investigation.
| Nearest mapped fault | Midland fault zone — 2.0 mi (3.3 km) |
| Liquefaction zone | 82% |
Dam inundation, aircraft noise & air quality
99% of Discovery Bay lies within a state-reviewed dam-failure inundation area; annual average fine-particle (PM2.5) concentration across its census tracts is 8.8 μg/m³, and its composite pollution burden ranks around the 18th percentile statewide.
| Dam-failure inundation area | 99% |
| Annual PM2.5 (tract average) | 8.8 μg/m³ |
| Pollution burden percentile (statewide) | ~18 |
Frequently asked questions
- Is Discovery Bay in a wildfire hazard severity zone?
- CAL FIRE's current Fire Hazard Severity Zone maps do not designate any zones within Discovery Bay. Individual properties near the boundary can still fall inside a neighboring zone — check the exact address on the map.
- Is Discovery Bay in a FEMA flood zone?
- 31% of Discovery Bay lies within a FEMA Special Flood Hazard Area (1% annual chance, zones A/AE/AH/AO); 17% is in the 0.2% annual chance (500-year) area. Federally backed mortgages in a Special Flood Hazard Area generally require flood insurance.
- What earthquake faults and seismic zones affect Discovery Bay?
- The nearest mapped fault, the Midland fault zone, is about 2.0 mi (3.3 km) from the center of Discovery Bay. 82% of its area is in a state-designated liquefaction zone of required investigation.
- How do I check a specific address in Discovery Bay?
- Use the free sitelume interactive map at https://sitelume.com — search any Discovery Bay address to see which mapped zones it falls in, layer by layer.
Nearby in Contra Costa County
Sources: CAL FIRE Fire Hazard Severity Zones; FEMA National Flood Hazard Layer; USGS Quaternary Faults; CGS Seismic Hazard Zones & Alquist-Priolo zones; Cal OES dam inundation maps; county ALUC noise contours; CalEnviroScreen 4.0. Area shares are computed against each place’s Census TIGER boundary (last computed 2026-07-24). Boundaries and zone designations change; always verify with the issuing agency.